selectors, descriptors, more interrupt init

[3sys] / sys1 / kern / src / intr.asm

diff --git a/sys1/kern/src/intr.asm b/sys1/kern/src/intr.asm
index dd35095..0d73c71 100644 (file)
--- a/sys1/kern/src/intr.asm
+++ b/sys1/kern/src/intr.asm
@@ -4,7 +4,14 @@
        extern intr_handler
 
 PIC1_CMD_PORT  equ 0x20
+PIC1_DATA_PORT equ 0x21
 PIC2_CMD_PORT  equ 0xa0
+PIC2_DATA_PORT equ 0xa1
+
+ICW1_ICW4_NEEDED equ 0x01
+ICW1_INIT      equ 0x10
+ICW4_8086      equ 0x01
+
 OCW2_EOI       equ 0x20
 OCW3_ISR       equ 0x0b
 
@@ -23,6 +30,48 @@ idtlim       dw 0
 idtbase dd 0
 
 
+       global prog_pic
+prog_pic:
+       ; send ICW1 saying we'll follow with ICW4 later
+       mov al, ICW1_INIT | ICW1_ICW4_NEEDED
+       out PIC1_CMD_PORT, al
+       ; send ICW2 with IRQ remapping
+       mov al, [esp + 4]
+       out PIC1_DATA_PORT, al
+       add al, 8
+       out PIC2_DATA_PORT, al
+       ; send ICW3 to setup the master/slave relationship
+       ; ... set bit3 = 3rd interrupt input has a slave
+       mov al, 4
+       out PIC1_DATA_PORT, al
+       ; ... set slave id to 2
+       mov al, 2
+       OUT PIC2_DATA_PORT, al
+       ; send ICW4 to set 8086 mode (no calls generated)
+       mov al, ICW4_8086
+       out PIC1_DATA_PORT, al
+       out PIC2_DATA_PORT, al
+       ; done, reset the data port to 0
+       xor al, al
+       out PIC1_DATA_PORT, al
+       out PIC2_DATA_PORT, al
+       ret
+
+
+       global end_of_irq
+end_of_irq:
+       mov eax, [esp + 4]
+       cmp eax, 8
+       jb .eoi_master
+       ; cascaded IRQ, send EOI to slave PIC first
+       mov al, OCW2_EOI
+       out PIC2_CMD_PORT, al
+.eoi_master: ; send EOI to master PIC
+       mov al, OCW2_EOI
+       out PIC1_CMD_PORT, al
+       ret
+
+
        ; special entry point for IRQ7 to catch and disregard spurious interrupts
        global intr_entry_irq7_verify
 intr_entry_irq7_verify:
@@ -54,12 +103,14 @@ intr_entry_irq15_verify:
 
 
 %macro intr_entry_err 2
+       global intr_entry_%2
 intr_entry_%2:
        push dword %1   ; push interrupt number
        jmp intr_entry_common
 %endmacro
 
 %macro intr_entry_noerr 2
+       global intr_entry_%2
 intr_entry_%2:
        push dword 0    ; push dummy error code
        push dword %1   ; push interrupt number
@@ -89,7 +140,6 @@ intr_entry_common:
        intr_entry_err 12, stack
        intr_entry_err 13, prot
        intr_entry_err 14, page
-       intr_entry_noerr 15, rsvd
        intr_entry_noerr 16, fpu
        intr_entry_err 17, align
        intr_entry_noerr 18, mce